Oh my god! Google is going to launch a remote hard disk service "a few months from now" according to "people familiar with the matter". Says who? Says the Wall Street Journal. Two years ago.

As our editor Patrick Goss points out, this particular story has been around for a long time and sooner or later it will be true. But what about the stories that aren't true and never will be?

More often than not, we - that is, bloggers, forum users, Twitterers and the like - will link to an interesting or scary news story when it's first published. How many of us go back to check whether the story stands up, or rewrite our blog posts if the story turns out to be wrong?

The 'post first, ask questions later' culture doesn't do much damage when we're just talking about tech. If Google doesn't bring out a GDrive this year, nobody will die. But we don't just blog and post about tech.

We blog and post about the same things the newspapers cover: science, politics and health. If the stories we link to and comment on turn out to be wrong, which they often are, the consequences can be serious.

Last week, my 15-month-old daughter went for her MMR vaccine. It's not a particularly pleasant thing and the side-effects aren't funny, but the alternatives - childhood measles kills, mumps can cause deafness and rubella can have horrific effects on unborn children if pregnant women are infected - don't bear thinking about.

But online you'll find endless blogs regurgitating newspaper scare stories about MMR causing autism: stories that, almost without exception, have been proven wrong. The blogs rarely, if ever, mention that and well-meaning but uninformed parents post those links in forums.

So parents look on the internet for information about MMR vaccines and they read about the apparent dangers. Then they don't get their children vaccinated and, according to the Department of Health, in some parts of London the vaccination rate has fallen to 50%.

The result? 14 years after measles was essentially eradicated in the UK, it's back. This isn't a nasty bug. It's an incredibly infectious, potentially lethal disease that in the 1960s was killing six million people a year.

The online echo chamber spreads bad information. You name it, it's out there: quackery, lies about public figures (Steve Jobs died again the other day), baseless health scares, killer Wi-Fi, exaggerated or entirely invented stories that show immigrants in a bad light, talk about scary laws that don't exist, or... you get the idea. A lot of it comes from stories that seemed plausible, but that later turned out to be false.

The blogging finger posts and, having posted, moves on. But the internet doesn't. Search engine spiders crawl our old posts, add them to the index and show them to searchers long after we've forgotten what we've written.

In the immortal words of Spider-Man's uncle, "with great power comes great responsibility". We have great power, but with it comes the responsibility to ensure we're not spinning a web of lies.